const str = "hello world";
console.log(typeof str) // string
const bol = true;
console.log(typeof bol) // boolean
const num = 123;
console.log(typeof num)  // number
const und = undefined;
console.log(typeof und)  // undefined
const nul = null;
console.log(typeof nul)     // object
const sym = Symbol('hello')
console.log(typeof sym)   // symbol
const obj = {
    name: 'hello',
    age: 18
}
console.log(typeof obj)     // object

const arr = [1, 2, 3, 4, 5]
console.log(typeof arr)    // object

function fn() {
    console.log('hello world')
}

console.log(typeof fn)   // function


const date = new Date()
console.log(typeof date)   // object

class Person {
    constructor(name, age) {
        this.name = name;
        this.age = age;
    }
}
console.log(typeof Person)   // function

const reg = /\d+/g
console.log(typeof reg)   // object

const oString = new String('hello world')
console.log(typeof oString)   // object
console.log(oString.__proto__)







